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Septic Tanks

JDP offers a range of septic tanks designed to settle the effluent, for situations where there is no mains drainage for the domestic sewage waste to discharge. Capacities available as standard: 2,800 litres - 54,000 litres. Other sizes available upon request.

Septic Tanks are historically the most common solution. However they do not treat the sewage, they only settle it. Because of even stricter environmental regulations septic tanks have become less common. The effluent cannot be discharged directly into a water course, and so a filter bed in a herringbone layout, constructed of smooth internal half perforated pipe, usually to EN1401-1 standard is required as part of the system to break down the biological matter. This means that the ground conditions and correct design and installation of the filter bed are critical to the performance of the system.

Features & Benefits
  • Low cost installation and maintenance
  • Lockable cover
  • Available in GRP or PE

The range of septic tanks provides an economic solution for anything from a single dwelling upwards, with the clarified effluent discharging to an underground filterbed system.

To ensure a septic tank is suitable the following information is essential:

  1. Discharge will not be directly into a water course (stream, lake etc).
  2. Consent to discharge from the EA (England & Wales) or SEPA (Scotland).
  3. Results of a percolation test based on BS6297 recommendations to establish size of filter bed required.

NB. Do not be tempted to install a septic tank as a cheap option without the necessary consent. It could prove a very costly mistake.

All standard septic tanks are supplied with a 1m invert inlet. For deeper inverts heavy duty version should be used.

Siting the Unit

  1. British Standard BS: 6297-1983 recommends that sewage treatment works should be as far away from habitable buildings as is economically practicable. The direction of the prevailing wind should be considered in relation to any properties when siting the works. The sludge emptying contractor’s vehicle will probably have a maximum reach of 30 metres, but the depth from the ground level to the bottom of the tank must not exceed 5 metres.
  2. The installation should be carried out in accordance with the requirements of the Construction and Building Regulations. An inspection chamber should be installed upstream of the Treatment Plant. For discharge quality sampling purposes a sampling chamber can be provided (optional extra).


  • Read Full Installation Guide provided with delivery of goods.
  • Ensure Building Regulation approval.
  • Ensure consent of discharge is approved from the environment agency.
  • Ensure access for desludging tanker. (Building regulations suggest 30m max).
  • Check orientation and heights of inlet and outlets.
  • Use a pump to keep excavation clean and free from rising ground water during installation.


  • Use the correct backfill material.
  • Site tank at furthest practical location from habitable dwellings. Most building regulations recommend a minimum of 7m.
  • Fit the correct cover & frame (pedestrian duty) LOCKABLE.
  • Consider drainage falls, generally 1 in 60/70 between house and tank and max. 1 in 200 for filter bed system.
  • Lift the tank using adequate ropes or slings through both of the lugs fitted either side of the neck.


  • Subject the tank to impact or contact with sharp edges.
  • Add neck extensions to the tank, nor, build a brick manhole above the tank neck (as this increases burial depth of the tank beyond that which it was designed for). We do not recommend extending the neck of the tank under any circumstances.
  • Install tank deeper than the depth that the fitted neck will allow.
  • Install in trafficked areas without a suitable load bearing slab.
  • Site the tank so that it is subjected to excess ground pressure (e.g. sloping sites) or applied loads such as may be generated by the proximity of vehicular traffic.
  • Lift using only one of the lugs.
  • Fill an unsupported tank.

Service Agreement

Although of a minimal nature, it is advised that the plant is serviced periodically to help ensure many years of trouble-free operation. Service Agreements are available through your local JDP.

This is a requirement of the new PPG4 guidelines.

Sewage Treatment Solutions Products